Heparanase inhibitor OGT 2115 induces prostate cancer cell apoptosis via the downregulation of MCL­1.

Heparanase (HPSE), an endo-ß-D-glucuronidase, cleaves heparan sulfate and serves an important role in the tumor microenvironment and thus in tumorigenesis. HPSE is known to promote tumor cell evasion of apoptosis. However, the underlying mechanism of this requires further study. In the present study, the results demonstrated that myeloid cell leukemia-1 (MCL-1), an antiapoptotic protein, and HPSE were upregulated in prostate cancer tissues compared with adjacent normal tissues. In addition, the HPSE inhibitor, OGT 2115, inhibited PC-3 and DU-145 prostate cancer cell viability in a dose-dependent manner, with IC50 values of 20.2 and 97.2 µM, respectively. Furthermore, annexin V/PI double-staining assays demonstrated that OGT 2115 induced apoptosis in prostate cancer cells. OGT 2115 treatment markedly decreased MCL-1 protein expression levels, whereas RNA interference-mediated downregulation of MCL-1 and OGT 2115 drug treatment synergistically induced apoptosis in PC-3 and DU-145 cells. In vivo, OGT 2115 40 mg/kg (ig) significantly inhibited PC-3 cell xenograft growth in nude mice and increased the positive TUNEL staining rate of xenograft tissues. It was therefore hypothesized that MCL-1 was an important signaling molecule in OGT 2115-induced apoptosis. The results of the present study also demonstrated that the proteasome inhibitor, MG-132, markedly inhibited the downregulation of MCL-1 protein expression levels induced by OGT 2115. However, the protein synthesis inhibitor, cycloheximide, did not affect the role of OGT 2115 in regulating MCL-1. In summary, the results of the present study demonstrated that the proapoptotic activity of OGT 2115 was achieved by downregulating MCL-1.

Exosome-derived long noncoding RNAs: Mediators of host-Plasmodium parasite communication.

Overcoming challenges associated with malaria eradication proves to be a formidable task due to the complicated life cycle exhibited by the malaria parasite and the lack of safe and enduring vaccines against malaria. Investigating the interplay between Plasmodium parasites and their mammalian hosts is crucial for the development of novel vaccines. Long noncoding RNAs (lncRNAs) derived from Plasmodium parasites or host cells have emerged as potential signaling molecules involved in the trafficking of proteins, RNA (mRNAs, miRNAs, and ncRNAs), and DNA. These lncRNAs facilitate the interaction between hosts and parasites, impacting normal physiology or pathology in malaria-infected individuals. Moreover, they possess the capacity to regulate immune responses and associated signaling pathways, thus potentially influencing chromatin organization, epigenetic modifications, mRNA processing, splicing, and translation. However, the functional role of exosomal lncRNAs in malaria remains poorly understood. This review offers a comprehensive analysis of lncRNA and exosomal lncRNA profiles during malaria infection. It presents an overview of recent progress in elucidating the involvement of exosomal lncRNAs in host-parasite interactions. Additionally, potential exosomal lncRNAs linked to the domains of innate and adaptive immunity in the context of malaria are proposed. These findings may contribute to the discovery of new diagnostic and therapeutic strategies for malaria. Furthermore, the need for additional research was highlighted that aimed to elucidate the mechanisms underlying lncRNA transportation into host cells and their targeting of specific genes to regulate the host's immune response. This knowledge gap presents an opportunity for future investigations, offering innovative approaches to enhance malarial control. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Small Molecule-RNA Interactions RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease.

Plasmodium manipulates the expression of host long non-coding RNA during red blood cell intracellular infection.

BACKGROUND: Parasites interact with their host through "direct" and/or "indirect" mechanisms. Plasmodium, for example, either mediates direct physical interactions with host factors or triggers the immune system of the host indirectly, leading to changes in infectious outcomes. Long non-coding RNAs (lncRNAs) participate in regulating biological processes, especially host-pathogen interactions. However, research on the role of host lncRNAs during Plasmodium infection is limited. METHODS: A RNA sequencing method (RNA-seq) was used to confirm the differential expression profiles of lncRNAs in Plasmodium yeolii 17XL (P.y17XL)-infected BALB/c mice. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to elucidate the potential functions of Plasmodium-induced genes. Subsequently, the effect of specific lncRNAs on the modulation of immune-related signaling pathways in malaria was determined by fluorescence-activated cell sorting, western blot and enzyme-linked immunosorbent assay. RESULTS: The data showed that in P.y17XL-infected BALB/c mice, Plasmodium upregulated the expression of 132 lncRNAs and downregulated the expression of 159 lncRNAs. Differentially expressed lncRNAs clearly associated with malaria infection were annotated, including four novel dominant lncRNAs: ENMSUSG00000111521.1, XLOC_038009, XLOC_058629 and XLOC_065676. GO and KEGG pathway analyses demonstrated that these four differentially expressed lncRNAs were associated with co-localized/co-expressed protein-coding genes that were totally enriched in malaria and with the transforming growth factor beta (TGF-ß) signaling pathway. Using the models of P.y17XL-infected BALB/c mice, data certified that the level of TGF-ß production and activation of TGF-ß/Smad2/3 signaling pathway were obviously changed in malaria infection. CONCLUSIONS: These differentially expressed immune-related genes were deemed to have a role in the process of Plasmodium infection in the host via dendritic/T regulatory cells and the TGF-ß/Smad2/3 signaling pathway. The results of the present study confirmed that Plasmodium infection-induced lncRNA expression is a novel mechanism used by Plasmodium parasites to modify host immune signaling. These results further enhance current understanding of the interaction between Plasmodium and host cells.

Human umbilical cord-derived mesenchymal stem cells ameliorate insulin resistance via PTEN-mediated crosstalk between the PI3K/Akt and Erk/MAPKs signaling pathways in the skeletal muscles of db/db mice.

BACKGROUND: Globally, 1 in 11 adults have diabetes mellitus, and 90% of the cases are type 2 diabetes mellitus. Insulin resistance is a central defect in type 2 diabetes mellitus, and although multiple drugs have been developed to ameliorate insulin resistance, the limitations and accompanying side effects cannot be ignored. Thus, more effective methods are required to improve insulin resistance. METHODS: In the current study, db/m and db/db mice were injected with human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) via tail vein injection, intraperitoneal injection, and skeletal muscle injection. Body weight, fasting blood glucose, and the survival rates were monitored. Furthermore, the anti-insulin resistance effects and potential mechanisms of transplanted HUC-MSCs were investigated in db/db mice in vivo. RESULTS: The results showed that HUC-MSC transplantation by skeletal muscle injection was safer compared with tail vein injection and intraperitoneal injection, and the survival rate reached 100% in the skeletal muscle injection transplanted mice. HUC-MSCs can stabilize localization and differentiation in skeletal muscle tissue and significantly ameliorate insulin resistance. Potential regulatory mechanisms are associated with downregulation of inflammation, regulating the balance between PI3K/Akt and ERK/MAPK signaling pathway via PTEN, but was not associated with the IGF-1/IGF-1R signaling pathway. CONCLUSIONS: These results suggest HUC-MSC transplantation may be a novel therapeutic direction to prevent insulin resistance and increase insulin sensitivity, and skeletal muscle injection was the safest and most effective way.

Plasmodium yoelii 17XL infection modified maturation and function of dendritic cells by skewing Tregs and amplificating Th17.

BACKGROUND: Emerging data has suggested that Tregs, Th17, Th1 and Th2 are correlated with early immune mechanisms by controlling Plasmodium infection. Plasmodium infection appeared to impair the antigen presentation and maturation of DCs, leading to attenuation of specific cellular immune response ultimately. Hence, in this study, we aim to evaluate the relevance between DCs and Tregs/Th17 populations in the process and outcomes of infection with Plasmodium yoelii 17XL (P.y17XL). METHODS: DCs detection/analysis dynamically was performed by Tregs depletion or Th17 neutralization in P.y17XL infected BALB/c mice via flow cytometry. Then the levels of cytokines production were detected using enzyme-linked mmunosorbent assay (ELISA). RESULTS: Our results indicated that Tregs depletion or Th17 neutralization in BALB/c mice infected with P.y17XL significantly up-regulated the percentages of mDC and pDC, increased the expressions of major histocompatibility complex (MHC) class II, CD80, CD86 on DCs and the levels of IL-10/IL-12 secreted by DCs, indicating that abnormal amplification of Tregs or Th17 may damage the maturation and function of DCs during the early stage of malaria infection. Interestingly, we also found that the abnormal amplification of Th17, as well as Tregs, could inhibit the maturation of DCs. CONCLUSIONS: Tregs skewing or Th17 amplification during the early stage of malaria infection may inhibit the maturation and function of DCs by modifying the subsets of DCs, expressions of surface molecules on DCs and secretion mode of cytokines.

VHL regulates NEK1 via both HIF-2α pathway and ubiquitin-proteasome pathway in renal cancer cell.

Both Von Hippel-Lindau tumor suppressor (VHL) and Never-in-mitosis A (NIMA)-related kinase 1 (NEK1) are involved in primary cilium formation, but whether VHL could regulate NEK1 is unknown. Here, we demonstrated that renal cancer cells Caki-1 and ACHN with wild-type VHL expressed lower level of NEK1 than that of VHL-defective cells including 786-O, 769-P and A498 cells. VHL-overexpression down-regulated NEK1 in 769-P cells, while VHL-knockdown up-regulated NEK1 in Caki-1 cells. In addition, we found the hypoxia response element (HRE) in the promoter sequence of NEK1 and hypoxia induced NEK1 expression both in vitro and in vivo. HIF-2α knockdown blocked hypoxia induced NEK1 upregulation instead of HIF-1α, which indicates that NEK1 may be a new target of HIF-2α. Moreover, we confirmed the association between VHL and NEK1 in Caki-1 cell, then showed VHL promoted NEK1 protein degradation and ubiquitination. In conclusion, our findings showed VHL regulates NEK1 via both HIF-2α pathway and ubiquitin-proteasome pathway in renal cancer cells.

Combinatorial Antitumor Effect of Rapamycin and ß-Elemene in Follicular Thyroid Cancer Cells.

Background. mTOR signaling would be a promising target for thyroid cancer therapy. However, in clinical trials, objective response rate with mTOR inhibitor monotherapy in most cancer types was modest. A new focus on development of combinatorial strategies with rapalogs is increasing. Objective. Investigating the combinatorial antitumor effect of rapamycin and ß-elemene in follicular thyroid cancer cells. Methods. MTT assay was used to determine the FTC-133 cell proliferation after culturing with rapamycin and/or ß-elemene. To analyze their combinatorial effect, immunoblotting was performed to analyze the activation status of AKT. Moreover, ß-elemene attenuated rapamycin-induced immunosuppression was tested in mice. Results. Combination of rapamycin and ß-elemene exerted significant synergistic antiproliferative effects in FTC-133 cell lines in vitro, based on inhibiting the AKT feedback activation induced by rapamycin. In vivo, the ß-elemene could attenuate rapamycin-induced immunosuppression via reversing imbalance of Treg/Th17, with the underlying mechanism needed to be declared. Conclusions. We demonstrate that the novel combination of mTOR inhibitor with ß-elemene synergistically attenuates tumor cell growth in follicular thyroid cancer, which requires additional preclinical validation.

Exosomal Long Noncoding RNAs are Differentially Expressed in the Cervicovaginal Lavage Samples of Cervical Cancer Patients.

BACKGROUND: As the second leading cause of cancer morbidity and death in women, cervical cancer remains an important public health problem worldwide. Novel biomarkers with high sensitivity and specificity for the early detection and diagnosis of cervical cancer are urgently needed. Increasing evidence shows that long noncoding RNAs (lncRNAs) are differentially expressed in cancer tissues and may serve as diagnostic markers. In multiple tumor types, exosomes harboring lncRNAs are actively released from tumor cells. In this study, we investigate the potential association of exosomal lncRNA expression with cervical cancer. METHODS: Cervicovaginal lavage specimens were collected from patients with cervical cancer and cancer-free volunteers who are HPV-positive or HPV-negative. Exosomes in these specimens were isolated by ultracentrifugation and confirmed by transmission electron microscopy. The exosomal lncRNAs HOTAIR, MALAT1, and MEG3 were quantified by qRT-PCR. RESULTS: Expression of HOTAIR, MALAT1 and MEG3 was predominantly observed in cervical cancer-derived exosomes in cervicovaginal lavage samples. The expression levels of lncRNAs were significantly different in exosomes isolated from cervical cancer patients compared to normal controls. CONCLUSIONS: Our data suggest that lncRNAs in exosomes isolated from cervicovaginal lavage are differentially expressed in cervical cancer patients and cancer-free volunteers. Exosomal lncRNAs may have great potential to be used for the early detection and diagnosis of cervical cancer, and serve as convenient and noninvasive biomarkers.

Gout and Risk of Myocardial Infarction: A Systematic Review and Meta-Analysis of Cohort Studies.

INTRODUCTION: A high incidence of myocardial infarction among patients with gout has been suggested by several observational studies. We performed a meta-analysis to evaluate the association between gout and the risk of myocardial infarction. MATERIALS AND METHODS: The PubMed and Embase databases were searched from inception to October 2014 for cohort studies that evaluating the association between gout and the risk of myocardial infarction. Summary estimates were derived using a random-effects model and reported as relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: Five studies involving 8,656,413 participants with a total of 1000 MI events were included. Overall, gout was associated with an increased risk of myocardial infarction (RR 1.45; 95% CI, 1.19-1.75; p<0.001), and the association referred to non-fatal myocardial infarction (RR 1.29; 95% CI, 1.19-1.39; p <0.001) but not fatal myocardial infarction (RR 1.11; 95% CI, 0.96-1.28; p = 0.174). The increased risk was observed in both women (RR 1.62; 95% CI, 1.18-2.21; p = 0.003) and men (RR 1.45; 95% CI, 1.21-1.74; p <0.001). Stratified analysis revealed a gradual increase in myocardial infarction risk with a younger age of gout onset (age 20-44 years old (RR 2.82; 95% CI, 1.38-5.79; p = 0.05); 45-69 years old (RR 1.85; 95% CI, 1.22-2.82; p = 0.04); ≥70 years old (RR 1.52; 95% CI, 1.22-1.88; p <0.001)). CONCLUSION: This meta-analysis suggests that patients with gout have an increased risk of myocardial infarction.

The tumor suppressor pVHL down-regulates never-in-mitosis A-related kinase 8 via hypoxia-inducible factors to maintain cilia in human renal cancer cells.

NEK8 (never in mitosis gene A (NIMA)-related kinase 8) is involved in cytoskeleton, cilia, and DNA damage response/repair. Abnormal expression and/or dysfunction of NEK8 are related to cancer development and progression. However, the mechanisms that regulate NEK8 are not well declared. We demonstrated here that pVHL may be involved in regulating NEK8. We found that CAK-I cells with wild-type vhl expressed a lower level of NEK8 than the cells loss of vhl, such as 786-O, 769-P, and A-498 cells. Moreover, pVHL overexpression down-regulated the NEK8 protein in 786-O cells, whereas pVHL knockdown up-regulated NEK8 in CAK-I cells. In addition, we found that the positive hypoxia response elements (HREs) are located in the promoter of the nek8 sequence and hypoxia could induce nek8 expression in different cell types. Consistent with this, down-regulation of hypoxia-inducible factors α (HIF-1α or HIF-2α) by isoform-specific siRNA reduced the ability of hypoxia inducing nek8 expression. In vivo, NEK8 and HIF-1α expression were increased in kidneys of rats subjected to an experimental hypoxia model of ischemia and reperfusion. Furthermore, NEK8 siRNA transfection significantly blocked pVHL-knockdown-induced cilia disassembling, through impairing the pVHL-knockdown-up-regulated NEK8 expression. These results support that nek8 may be a novel hypoxia-inducible gene. In conclusion, our findings show that nek8 may be a new HIF target gene and pVHL can down-regulate NEK8 via HIFs to maintain the primary cilia structure in human renal cancer cells.

Effects of clinical isolates of Streptococcus pneumoniae on THP-1 human monocytic cells.

Twenty­three clinical Streptococcus pneumoniae (SP) strains were isolated from blood and sputum specimens from the Second Affiliated Hospital of Wenzhou Medical College in 2009. These strains and the ATCC 49619 standard strain were cultured and suspended in normal saline (at a turbidity of 1.0 McFarland). The production of interleukin (IL)­8, intracellular adhesion molecule­1 (ICAM­1) and IL­10 in THP­1 cells following stimulation with the SP suspension was analyzed by an enzyme-linked immunosorbent assay. The concentrations of IL­8, ICAM­1 and IL­10 from the THP­1 monocytes were greater than those of the blank control following stimulation with the SP suspension. No significant difference was identified in the levels of IL­8, ICAM­1 and IL­10 secretion between THP­1 monocytes stimulated by blood­borne SP (bb­SP) and sputum­borne SP (sb­SP).